I'm not an authority, but I think I know what you're getting at. I believe a rod with more give in the tip will transmit less vibrations to the handle, all other things the same. Thus, I don't think you'll feel as much with a 6-10 as a 8-12 on the same model/length. The flex of the tip dampens the vibraions. The most sensative rod I've used was a 5.5 foot heavy/fast action bass rod. Shorter and lighter rods are also more sensative in my experience.